摘要:
Es ist ein passiv modengekoppelter Faserringlaser (LAS) zur Erzeugung optischer Pulse, deren Pulsfolgefrequenz einstellbar ist, angegeben. Der modengekoppelte Faserringlaser (LAS) beinhaltet eine Erbium dotierte Faser (ER), einen Ringresonator (RES), eine Pumplichtquelle (PUMP), einen optischen Modulator (MOD) und eine Rückkoppelschleife (RS). Ein Teil des Signallichts, welches sich aus dem Rauschen heraus bildet und welches sich aus mehreren Pulsfolgefrequenzen zusammensetzt, wird in der Rückkoppelschleife (RS) zu einem Steuersignal verarbeitet, das auf den Steuereingang des optischen Modulators (MOD) gekoppelt wird. In der Rückkoppelschleife (RS) befindet sich ein einstellbares Filter, welches die gewünschte Pulsfolgefrequenz aus dem Signallicht herausfiltert. Damit bilden sich optische Pulse einer bestimmten Pulsfolgefrequenz im Ringresonator (RES) und am Ausgang (OUT) des passiv modengekoppelten Faserringlasers (LAS) aus.
摘要:
A figure-8 loop laser (11) having a controllable phase shifter (37) in a Sagnac loop (15) (non-linear amplifying loop mirror). In one embodiment, the controllable phase shifter, which is constructed from a half-wave plate and pair of Faraday optical rotators (55,57) provides a switchable non-reciprocal 180-degree phase shifter that allows the birefringence of the fiber loop to be adjusted during continuous wave operation. The phase shifter (37) is activated during continuous wave operation to find a minimum threshold and then is turned off, placing the laser in optimum state for mode locking. In another embodiment, a time varying phase modulator is used as the controllable phase shifter, which provides a means of both starting and controlling optical pulses.
摘要:
EXTENDED LASER LIFE may be obtained by measuring, with an ammeter AM, the discharge current applied to a laser (either linear or a ring laser gyro RLG), measuring the intensity of the resulting light beam with an intensity monitor IM, calculating the noise with an integrated circuit IC, and maintaining the discharge current at the lowest level possible which is consistent both with maintaining the intensity above the intensity service limit and the noise below the noise service limit.
摘要:
An electrically tunable optical oscillator. An acoustooptically tunable filter (F1) is located in a feedback path of an optical oscillator. The filter non-collinearly diffracts the light signal to selectively tune the osciallator. In accordance with one aspect of the invention, the feedback path includes an optical isolator (I) so that light can rotate through the feedback path in only one direction, and a plurality of 1/2 wave retardation plates (R1,R2) for shifting the polarization of the light signal.